Selective production and kinetic analysis of thermally equilibrated N₂(B³Π_g, v = 0) and N₂(W³Δ_u, v = 0)

Abstract

The kinetic behavior of triplet-state molecular nitrogen, N 2 (B 3 P g , v ¼ 0) and N 2 (W 3 D u , v ¼ 0), was examined. These molecules were produced by excitation transfer between Xe(6s[3/2] 1 ) and ground-state N 2 followed by collisional vibrational relaxation. Xe(6s[3/2] 1 ) was produced by two-photon laser excitation of Xe(6p[1/2] 0 ) followed by concomitant amplified spontaneous emission (ASE). The weighted averages of the rate constants for the quenching of N 2 (B, v ¼ 0) and N 2 (W, v ¼ 0) were determined for 15 molecules by measuring the decay profiles of N 2 (B, v ¼ 0). The observed rate constants are all one order of magnitude smaller than those reported for N 2 (B, v ! 1). The literature values for N 2 (B, v ! 1) must be the rate constants to produce neighbouring N 2 (W), from which N 2 (B) can be reproduced, and do not represent those for net quenching. In the reaction with H 2 (D 2 ), the production of H(D) atoms was confirmed to be one of the major exit channels, while the relaxation to N 2 (A 3 S þ u ) was found to be minor.

Production yields of H(D) atoms in the reactions of N2(AΣu+3) with C2H2, C2H4, and their deuterated variants

“…In some cases, metastable Xe atoms, such as Xe͑6s͓3/2͔ 2 ͒ and Xe͑6sЈ͓1/2͔ 0 ͒, are used instead of Ar͑4s 3 P 0,2 ͒. 18 The rate constant for the quenching of Xe͑6s͓3/2͔ 1 ͒ and that of equilibrated N 2 ͑B͒ and N 2 ͑W͒ by N 2 have been determined to be 1.4ϫ 10 −11 and 2.9 ϫ 10 −12 cm 3 s −1 , respectively. When these excited rare gas atoms are produced in glow discharges, the total pressure must be low, in the order of 100 Pa.…”

Active nitrogen and oxygen: Enhanced emissions and chemical reactions

“…Similarly, as for N 2 ða 1 R À u Þ, because of the very efficient N 2 (B 3 P g ) quenching by [26,41,72] N 2 and by [41,72] O 2 , and the even more efficient collisional mixing [4,72] of the coupled N 2 triplet states (that has a rate constant value higher by one order of magnitude than that reported in [72] for the electronic quenching of the N 2 (B 3 P g , m = 0) state), the N 2 (B 3 P g , m = 0), the N 2 (W 3 D u , m = 0) and their vibrationally excited homologous states are excluded from possible involvement in the enhancements of background afterglow N 2 1pbs emissions intensities by discharged O 2 .…”

H(D)-atom yields in the quenching of Xe(6s[3∕2]1) by methane, ethane, ethene, ethyne, and their deuterated isotopologues

“…9 The frequencydoubled output of a dye laser ͑Lambda Physik, LPD3000E͒ pumped with a Q-switched Nd:YAG ͑yttrium aluminum gar-net͒ laser ͑Quanta-Ray, GCR-170͒ at 249.6 nm was used to two-photon excite ground-state Xe to the 6p͓1/2͔ 0 level. 9 The frequencydoubled output of a dye laser ͑Lambda Physik, LPD3000E͒ pumped with a Q-switched Nd:YAG ͑yttrium aluminum gar-net͒ laser ͑Quanta-Ray, GCR-170͒ at 249.6 nm was used to two-photon excite ground-state Xe to the 6p͓1/2͔ 0 level.…”

“…9 The Xe pressure was 267 Pa while the total pressure was kept constant at 13.3 kPa by adding He. 9 The Xe pressure was 267 Pa while the total pressure was kept constant at 13.3 kPa by adding He.…”

“…9 The Xe pressure was 267 Pa while the total pressure was kept constant at 13.3 kPa by adding He. 9 In the present work, the author checked the former results and found that the previous values are correct except for D 2 . The reciprocal time constant for the decay increased linearly with the quencher pressure.…”